The value of vegetation Researchers have constructed a network of the relatedness between products, providing insight into the economic question of why some countries can quickly climb the manufacturing ladder, while others fail to develop more sophisticated products. While the model may sound intuitive, this research is the first time that countries’ different economic growth patterns have been explained by a product network. Past economic theories have relied on a country’s productive factors (labor, land, infrastructure, etc.) or technological capabilities, but have disregarded product similarities when explaining a country’s growth. In a sense, the product network incorporates these other factors under one model.As part of a test of their model, the researchers asked if, given enough time, all countries could reach most of product space, particularly the richest parts. They found that the answer depends on the overall proximity of product space, as well as a country’s original positioning. For example, Chile and Korea have similar levels of production and export sophistication, but because Korea produces some core products, it can extend its sophisticated product line faster than Chile. The researchers even found that with countries that were developmentally similar, some were on a path to structural transformation while others seemed headed toward a dead end.“What surprised me along the year and a half that this work took was the broad set of implications and questions that were opened,” Hidalgo said. “There are many hard science studies on complex systems where the application of the findings is not well defined. Here we have a well defined area of application (industrial policy), yet the study lends itself for research in similar data sets. We are working on other areas of applications, such as research and health policy.”The researchers suggest that, for economic policy, estimating a country’s position in product space could have important consequences. For instance, countries in close proximity to other products could benefit the most from a relevant structural transformation, whereas countries at the periphery would need to make much longer jumps and would likely present a greater challenge to reform projects.“The proximity between products in the space increases as more countries export them in tandem,” Hidalgo explained. “Thus the movement of countries deforms the space. The technique does not provide a general solution for policymaking, but a new method to analyze and tailor policies for individual countries.” Product space networks of many nations can be seen at www.nd.edu/~networks/productspace/country.htm . Citation: Hidalgo, César, Klinger, Bailey, Barabási, Laszlo, and Hausmann, Ricardo. “The Product Space Conditions the Development of Nations.” Science, 27 July 2007, Vol. 317, 482-487.Copyright 2007 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Explore further Citation: Nation’s position in ‘product space’ determines economic growth (2007, August 29) retrieved 18 August 2019 from https://phys.org/news/2007-08-nation-position-product-space-economic.html
Explore further (PhysOrg.com) — Researchers studying the planet Venus have found that despite a lack of a magnetic field, the planet has magnetotails, which on Earth are part of the process known as the Northern and Southern Lights. This, as the team describes in their paper published in Science, is due to the solar wind interacting with the planet’s ionosphere. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. On Earth and other planets that do have a magnetic field, solar wind is deflected by the magnetism that surrounds the planet into the magnetosphere causing magnetic lines of force to break and reconnect, resulting in the show of lights in the night sky called an aurora. This process known as magnetic reconnection also causes the creation of magnetotails, or elongated stretches of the magnetosphere on the lee side of planets. This new research shows that Venus too has such magnetogtails, though the process of their creation is different.In analyzing data obtained from Venus Express, the probe sent by the European Space Agency, the researchers found that on Venus, the solar wind reacts with the ions in its ionosphere and in one instance resulted in what they describe as a magnetic plasma bubble stretching for some 2100 miles and lasting for just over a minute and a half. This they say is also an example of magnetic reconnection, albeit, one of a different kind.For years, researches have puzzled over mysterious flashes of light coming from Venus, and some have even speculated that they might be caused by magnetic reconnection, but until now lacked evidence. This new research adds strong credence to that theory and may also explain how some comet tails manage to disengage from their heads.As for whether the light generated by such instances of magnetic reconnection on Venus can truly be called an aurora, that remains up for debate. On Earth the Northern and Southern lights, also known as aurora borealis and aurora australis are named after the Roman goddess of dawn and thus are not tied to any specific scientific phenomenon, so it wouldn’t seem to be a stretch to use the same term for a similar effect discovered on another planet. Journal information: Science © 2012 PhysOrg.com Cluster opens a new window on ‘magnetic reconnection’ in the near-Earth space More information: Magnetic Reconnection in the Near Venusian Magnetotail, Science DOI: 10.1126/science.1217013ABSTRACTObservations with the Venus Express magnetometer and low-energy particle detector revealed magnetic field and plasma behavior in the near-Venus wake symptomatic of magnetic reconnection, a process that occurs in the Earth’s magnetotail but is not expected in the magnetotail of a non-magnetized planet like Venus. On 15 May 2006, the plasma flow in this region was toward the planet and the magnetic field component transverse to the flow was reversed. Magnetic reconnection is a plasma process that changes the topology of the magnetic field and results in energy exchange between the magnetic field and the plasma. Thus, the energetics of the Venus magnetotail resembles that of the terrestrial tail where energy is stored and later released from the magnetic field to the plasma. Citation: Venus found to have aurora type magnetotails (2012, April 6) retrieved 18 August 2019 from https://phys.org/news/2012-04-venus-aurora-magnetotails.html Venus. Photo courtesy of NASA
(Phys.org) —Researchers from Princeton University in the U.S. together with colleagues from Zhejiang University of Science and Technology in China have developed a new kind of atomic magnetometer that is just as sensitive as others of its kind but doesn’t need to be shielded from the Earth’s magnetic field. The team reports on their new device in the journal Physical Review Letters. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Explore further Journal information: Physical Review Letters Devices that can measure magnetic fields—magnetometers—are very useful in a wide variety of scientific applications. In recent years, such devices have been made more sensitive by using superconducting materials but they have the drawback of needing to be cryogenically cooled. Another approach has been to use atomic magnetometers—they don’t have to be super-cooled, but they do need to have shielding put in place to prevent Earth’s magnetic field from interfering with their readings. They work by using a pump laser to polarize the spin states of atoms inside the device. A probe laser is then used to read the spin precession once the device is ready to read a specific magnetic field—it’s all based on the Zeeman Effect that is induced by an external magnetic field.The new atomic magnetometer the group developed works essentially the same way as others of its kind, with two notable exceptions. The first is that the team uses a multi-pass cell—the probe laser makes many passes while reading the spin of the atoms in the device—typically rubidium vapor—this enhances the signal. The second difference is the team uses a technique to allow the polarizing to take place very quickly (within 1ms of laser pumping)—before relaxation of the spin states occurs. Doing so has the added benefit of helping to eliminate noise in the system allowing for more precise readings. The end result is an atomic magnetometer that is able to measure magnetism that is one hundred billion times smaller than the Earth’s field, without the need for shielding.Such a magnetometer is expected to be useful for such applications as measuring biological fields, geological instrumentation, experimental physics and even in land mine detection. The team that developed the new device isn’t resting on its laurels, however, they are currently looking at ways to make the device smaller and more portable. Record measurement of extremely small magnetic fields More information: Subfemtotesla Scalar Atomic Magnetometry Using Multipass Cells, Phys. Rev. Lett. 110, 160802 (2013) DOI: 10.1103/PhysRevLett.110.160802AbstractScalar atomic magnetometers have many attractive features but their sensitivity has been relatively poor. We describe a Rb scalar gradiometer using two multipass optical cells. We use a pump-probe measurement scheme to suppress spin-exchange relaxation and two probe pulses to find the spin precession zero crossing times with a resolution of 1 psec. We realize a magnetic field sensitivity of 0.54 fT/Hz1/2, which improves by an order of magnitude the best scalar magnetometer sensitivity and exceeds, for example, the quantum limit set by the spin-exchange collisions for a scalar magnetometer with the same measurement volume operating in a continuous regime. Citation: New atomic magnetometer doesn’t need to be shielded from Earth’s magnetic field (2013, April 26) retrieved 18 August 2019 from https://phys.org/news/2013-04-atomic-magnetometer-doesnt-shielded-earth.html © 2013 Phys.org Credit: J. Shi/Princeton University/PRL
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Explore further Planetary influences on young stellar disks (Phys.org)—An international team of astronomers, led by Markus Janson of Stockholm University in Sweden, has discovered mysterious sharp symmetric features around young double star, named AK Sco. The discovery is baffling scientists as they are still unsure about the nature of these features, pondering the possibilities that they are highly eccentric rings or two separate spiral arms in the disk around the star. Moreover, these features may have been caused by circumbinary planets interacting with the disk. The results were published on Dec. 14 in the arXiv journal. AK Sco, located about 460 light years from Earth, is a spectroscopic binary star in the Upper Centaurus–Lupus (UCL) stellar association. It is a relatively young system, at least in astronomical terms, as scientists estimate it to be from 10 to 20 million years old. Spectroscopic binaries are systems in which the stars are so close together that they appear as a single star even in a telescope. The only evidence of a binary star comes from the Doppler effect on its emitted light. Periodic Doppler shifts of the wavelengths of lines are seen in the spectrum, as the stars move through their orbits.Janson and his colleagues made the discovery using the European Southern Observatory’s (ESO) Very Large Telescope (VLT), located in Chile. The observations were conducted in April 2015 as a part of the Search for Planets Orbiting Two Stars (SPOTS) program. The scientists made use of the Spectro-Polarimetric High-contrast Exoplanet Research (SPHERE) instrument recently installed on VLT. SPHERE is a powerful planet finder and its objective is to detect and study new giant exoplanets orbiting nearby stars using a method known as direct imaging.Detecting the sharp features in near-infrared imaging of AK Sco’s disk was a surprise for the scientists as they expected to find rather exoplanets in the neighborhood. However, what they found, might not be planets at all.”We report the discovery of resolved scattered light emission from the circumbinary disk around the well-studied young double star AK Sco. The sharp morphology of the imaged feature is surprising, given the smooth appearance of the disk in its spectral energy distribution,” the astronomers wrote in the paper.They researchers have noticed that the central binary star has a semi-major axis of approximately 0.16 astronomical units or AU and that the disk appears to have a gap with an inner rim at 0.58 AU. The images of AK Sco obtained by the SPHERE instrument reveal that the system has ‘arms’ extending from each side of the central star almost symmetrically. The scientists also found out that these features constitute scattered radiation from off-axis material in the circumbinary disk.The mysterious sharp features could represent an eccentric ring of material surrounding a gap. The scientists note that such structures are often found in disks that contain rings of material with gaps inside them. However, other observations conducted by ESO’s Atacama Large Millimeter Array (ALMA) don’t support this theory.Another explanation taken into account by Janson and his colleagues is that these structures are spiral arms that could be induced through gravitational instability or through the influence of a planet or binary companion. These two spiral arms are wound in opposite directions—one unwinding clockwise and the other counter-clockwise. But the fact that the features are so apparently symmetric, speaks against this hypothesis.What is worth noticing, either of these scenarios mentioned earlier, may point to circumbinary exoplanets in the disk. The features could be created by one or several planets interacting with the disk.Whichever proposed theory is true, the authors of the paper highlight the importance of the new generation adaptive optics systems – like this installed on the SPHERE instrument – in the search of disks around stars. They hope that these features will detected more often in near future as a result of implementing new technology of observations. SPHERE high-contrast images of AK Sco. All images show the two arms of the disk discussed in the paper. Credit: Markus Janson et al. 2015 © 2015 Phys.org More information: Detection of Sharp Symmetric Features in the Circumbinary Disk Around AK Sco, arXiv:1512.04552 [astro-ph.SR] arxiv.org/abs/1512.04552AbstractThe Search for Planets Orbiting Two Stars (SPOTS) survey aims to study the formation and distribution of planets in binary systems by detecting and characterizing circumbinary planets and their formation environments through direct imaging. With the SPHERE Extreme Adaptive Optics instrument, a good contrast can be achieved even at small (<300 mas) separations from bright stars, which enables studies of planets and disks in a separation range that was previously inaccessible. Here, we report the discovery of resolved scattered light emission from the circumbinary disk around the well-studied young double star AK Sco, at projected separations in the ~13—40 AU range. The sharp morphology of the imaged feature is surprising, given the smooth appearance of the disk in its spectral energy distribution. We show that the observed morphology can be represented either as a highly eccentric ring around AK Sco, or as two separate spiral arms in the disk, wound in opposite directions. The relative merits of these interpretations are discussed, as well as whether these features may have been caused by one or several circumbinary planets interacting with the disk. Citation: Mysterious sharp symmetric features detected around young double star (2015, December 17) retrieved 18 August 2019 from https://phys.org/news/2015-12-mysterious-sharp-symmetric-features-young.html
Citation: Shipworm that eats rock instead of wood found in river in the Philippines (2019, June 19) retrieved 18 August 2019 from https://phys.org/news/2019-06-shipworm-wood-river-philippines.html Morphology of Lithoredo abatanica: (a) juvenile specimen (PMS-4313H); (b) small adult specimen (PMS-4134 W); (c) large adult specimen (holotype PMS-4312Y); (d) pallet pair outer face; (e) pallet pair inner face; (f) shell valves; (g) scanning electron micrograph of shell valve; (h) magnified region from (g) showing valve denticulation; (i) magnified region from (h). In, intestine; MC, mantle collar; Pa, pallet; Si, siphon; SV, shell valve. Scale bar (a–c) = 5 mm, (d–f) = 1 mm, (g–i) = 200 µm, 100 µm and 5 µm respectively. Credit: Proceedings of the Royal Society B: Biological Sciences (2019). DOI: 10.1098/rspb.2019.0434 New species of wood-munching (and phallic-looking) clams found at the bottom of the ocean More information: J. Reuben Shipway et al. A rock-boring and rock-ingesting freshwater bivalve (shipworm) from the Philippines, Proceedings of the Royal Society B: Biological Sciences (2019). DOI: 10.1098/rspb.2019.0434Press release This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.